You could say that “The Time Traveler’s Wife” is a science-fictiony romance about eternal love and all that sniffy, weepy stuff. Or you could think of it as a crazy story about a stalker who sweet-talks a little girl whom he later seduces when she’s a teenager only to then knock her up and emotionally, psychologically and spiritually knock her down again and again, as he hopscotches naked across the time-space continuum.

Of course one woman’s romantic fantasy can be another’s gas-lighted nightmare, which is why it’s easy to read Audrey Niffenegger’s chart-busting novel in such dramatically different ways. A chronological confusion, it turns on a contemporary romance between an unwilling time traveler, Henry, and the woman he marries, Clare. In the novel the romance comes across as airy and coy and unpersuasive. But what feels light on the page can seem exceedingly ponderous once a filmmaker transposes those words into the visual realm. It is, after all, one thing to read about a naked guy talking up a 6-year-old girl while he’s hiding in some bushes. It’s another thing entirely to watch the big, strapping, healthy Eric Bana groping the greens.

It isn’t his fault. Indeed, watching Mr. Bana frequently strut his seminude stuff, nimbly avoiding the full-frontal reveal even as he flashes some discreet cheek, is one of the few pleasures afforded by this often ridiculous, awkward, unsatisfying and dour melodramatic adaptation. A sometime librarian, Henry has been born with a genetic anomaly that causes him to take abrupt hops across time, losing his clothes in the process. He first meets Clare (a frumped-up Rachel McAdams) when he’s 28, and she’s a 20-year-old art student. She’s new to Henry, but she knows and adores him because he has been regularly visiting her since she was 6, popping in and out of her life, though always when he was older. (Got that?)

Much like Henry, the novel jumps all over the timeline and unfolds through alternating he-said, she-said, first-person voices. Notably it’s Henry who first describes an early, crucial encounter between his 36-year-old self and the self-possessed 6-year-old Clare, which shrewdly puts you right inside his (innocent) head. First-person narration in novels can make you feel intensely close to a character, as if you had crawled into another being. In the book you’re not only by Henry’s side when he’s hiding in those bushes: you’re also on his side, or at least that’s the idea. This means that by the time the 6-year-old Clare describes a similar encounter pages later, the potential ick factor has already been defused.

On the screen, however, because the camera hovers vaguely between her point of view and Henry’s — and because the director Robert Schwentke lays a heavy hand on every nuance and has made a dirge about love instead of an ode — the scene wobbles between unpersuasive comedy and outright creepiness, as does much of the movie. It’s instructive that when the book isn’t drooping under the weight of its metaphor (Men! They’re always leaving!), it makes room for pleasure amid the trauma. Ms. Niffenegger grasps the melodramatic truism that tears sting the strongest when the audience feels as if it had lost something, which helps explain her sales. By contrast, the filmmakers (the script is by Bruce Joel Rubin) shroud the movie in foreboding as Henry looks for some clothes, and you search for your smile.

Directed by Robert Schwentke; written by Bruce Joel Rubin, based on the novel by Audrey Niffenegger; director of photography, Florian Ballhaus; edited by Thom Noble; music by Mychael Danna; production designer, Jon Hutman; produced by Nick Wechsler and Dede Gardner; released by Warner Brothers Pictures. Running time: 1 hour 47 minutes.